Cores



United States Patent O "ce 3,152,498 CORES Burton A. Wyman, Cleveland, Ohio, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Aug. 31, 1961, Ser. No. 135,363 3 Claims. (Cl. 83-40) This invention relates generally to ballastic core constructions used for the control of fluorescent lamps, and more particularly to novel apparatus and process for cutting of laminae from magnetic strip material leaving substantially no scrap, with the cores being formed by the stacking of such laminae.

In making high reactance specialty transformers particularly wherein a magnetic shunt leg is provided between the two operating coils, there has been prior to the present invention an inability to efficiently produce laminations, of .the type illustrated, for example, in copending application Serial No. 705,581, filed December 27, 1957' by A. R. Cornell, entitled Transformer and Ballast Laminations, now abandoned and assigned to the same assignee as is the present application, by a die blanking and stripping operation that is relatively scrap free. In such prior productions the scrap often amounted to forty percent of the net usable punching weight of an entire blanking strip. The present invention provides for a substantially continuous feed blanking die layout operation which can produce stacked laminae with an efficiency such that approximately only two to five percent of the punching weight of `the entire strip in question ends up as scrap.

Accordingly, one of the objects of the present invention is to provide punching apparatus wherein relatively scrapless laminae can be blanked out with a minimum of Wasted material.

Another object of the present invention is to provide a substantially continuous feed and die mechanism Wherein relatively scrapless laminae can be punched out of a strip and be conveniently stacked for further treatment.

A still further object of the present invention is to provide a means to manufacture core laminations like those illustrated in the aforesaid copending application.

The above and other objects of this invention will become more apparent upon consideration of the following detailed description of preferred embodiments thereof when taken in connection with the attached drawings, in which:

FIGURE l is a partial top plan view of a die apparatus and strip of blanking material forming an embodiment of the principles of the present invention, and taken substantially along the reference lines I-I of FIG. 2;

FIG. 2 is a side elevational view of the apparatus and material of FIG. l including, in addition, a punching die; and

FIG. 3 is a top plan view of a core lamination as it appears in its assembled relationship after it is stamped out of a sheet of magnetic material, as illustrated in FIGS. 1 and 2.

AThe present invention generally resides in providing a die punching and stripping mechanism wherein laminae can be punched from a substantially continuously fed, strip blank material so that relatively no scrap or waste material results and such that certain blanked out or punched laminae are automatically stacked so as to be in condition for further treatment or use.

Referring more particularly to FIGS. l and 2 there is illustrated a die punch apparatus comprising a bed 12 and a punching die mechanism 14 (seen only in FIG. 2). Being fed between the bed 12 and punching die 14 is a strip of material 16, preferably a magnetic strip steel or a magnetic ferrite, such that punching operations can 3,l52,498 Patented Oct. 13, 1964 be performed thereon by the die and the bed as the strip 16 progresses through the apparatus 1t).

The strip 16 is fed into the apparatus 19 through the feed rollers 18 which are mechanically coupled (not shown) by any suitable, known method to the vertically moving punching die 14. The coupling can be either mechanically or electrically controlled, as desired. This coupling is employed such that the upward motion of the punching die 14 produces a rotary motion of the feed rollers 18 to advance the strip 16 in a manner which is Well known in punch press operations.

The die apparatus is so arranged that pilot holes 24 are made by pilot punches 22 in the strip 16 either in the first or second stages of progression of the strip 16 through the die. The pilot holes are illustrated as being made in the first stage in FIGS. l and 2. Other pilots 28 of the die apparatus 10 enter these previously pierced pilot holes 24 in a subsequent stage or stages of progression to provide accurate alignment of the strip 16 in the die apparatus 10. The pilot holes 24 can optionally be pierced in the laminate portion of the strip, as shown, or in the scrap portion of the strip. When in the laminae portion the pilot holes 24 can be used for assembling the laminae into stacks in the finished product and to screw clamp them together, when a finished lamination is relatively long, to reduce the noise level when operating.

The die 14 includes punches 34, 36, 38, 40 and 42 which serve to perform the dilferent punching operations necessary when the strip is placed between the die 14 and the bed 12. Corresponding to each of the above-mentioned punches are cavities 44, 46, 48, 50 and 52 through the bed 12 which serve not only to receive their respective punches after they pass through the top surface of the bed 12, but also to receive the punched laminae and the waste material from the strip 16. Thus, a portion, such as a first T-shaped lamina 54 (FIG. 3), is punched out of the strip 16 and is forced through the cavity 44 and into a chute 56 where it settles, and further laminae 54 are punched out and stacked in chute 56 until the desired quantity has been assembled for further treatment or use. Thus, it can be seen that it is advantageous to have pieces such as laminae 54 drop off into chutes 56 to form stocks which can be stacked in trays for later annealing to improve their magnetic properties.

When the strip 16 is iirst introduced into the apparatus 10 its leading edge first stops at stage A. The die punch 14 is then lowered and a lamina S4 is then punched out by the punch 34 and is forced into the cavity 44. Subsequent laminae 54 will be conformed to be stacked upon the first punched larnina 54. After this, the die punch 14 is raised and the front end of the strip 16 progresses to a second stage B. At this time the die punch 14 is again lowered and the punch 34 punches out a second lamina 54 while the punches 36 punch out slot sections (not shown) which drop through the cavities 44 and 46, respectively, and leave the slots 59 in the strip 16. Then, as before, the die punch 14 is again raised and the strip 16 progresses to stage C where a T-shaped lamina 60 (FIG. 3) is punched out by the die 38, two more slot sections are punched out by the punches 36, and another T-shaped lamina 54 is punched out by the punch 34, all of the respective items dropping through their respective cavities 48, 46 and 44 and accumulating in their respective chutes, where provided. From stage C the strip 16 moves to stage D wherein the punches 40 and 42 punch out the scrap sections (not shown). They also are forced through their respective cavities 50 and 52, with all of the preceding punches being simultaneously repeated, as is obvious.

In this initial progression of the strip 16 through the die apparatus 10, it should be noted that an entire blank as illustrated in FIG. l will not be stamped out because the strip 16 has only progressed to stage D so that only half of the blank is punched out by punch 42. This iS all that is necessary in the initial progression because the necessary front end cut on the end of remaining laminae or legs 68 has been achieved at this point. When the next step in the progression of the strip 16 through the die takes place the back notch 66 on each of the legs 68 will be punched out while the front notches '70 on the succeeding laminae legs will be simultaneously removed by the die punches 42. Also, in this next progression after the notch 66 is formed the projecting tooth separator 72 divides the legs 68 into two separate passages when they fall into the inclined chute 62 for further stacking in a usual fashion. It is seen that a cavity is not needed for the legs 68, for they fall beyond the end of the bed 12 directly into their respective chute 62.

It can be seen that once the strip has passed through an initial complete progression that the subsequent progressions are continuous and that concurrent stampings of a plurality of separate laminae parts takes place substantially with each section moving through a stage and being stamped simultaneously with other backwardly and forwardly located laminations. In this manner the complete progression is completed and the punching of laminations can proceed at a regular pace until the necessary quantity of component parts are accumulated and it is desired to stop the operation. At such a point the strip 16 can be severed by shear action at its rear by a stripper (not shown) if desired or it can be left as it is until it is desired to punch out more laminae.

After sufiicient quantities of the individual component laminae 54, 60 and 68 have been accumulated in the chutes S6, 57 and 62, respectively, and have been annealed, they are put together into a core arrangement as shown in FIG. 3. In this way the laminae 54 and 60 form the yoke of the core and the laminae 68 form the legs of the core so as to provide for an arrangement permitting an adjustable gap similar to that shown in the aforementioned copending application. The cutouts 59 in the yoke laminae 60 are primarily to provide leakage paths and air gaps where desired. However, if it is desired not to have the cutouts 59 in the yoke laminae 60 they can be eliminated simply by removing the punches 36 from the die 14.

It can be seen that only extremely small portions of the punchings are wasted in this type of layout so that it can readily be stated that the die layout progression as set forth is essentially scrapless. The notches 66 and 70 provide end shoulders around which clamping devices can be assembled to hold together the laminae which form the completed laminated core. The particular reasons for the configuration of the laminated core shown in FIG. 3 are also explained in the aforementioned copending application.

Accordingly, there has been disclosed a die apparatus and progression layout wherein it is possible to manufacture a substantially scrapless laminated core to achieve economies in both time and material heretofore unknown in the art. Since it is obvious that the invention can be embodied in other forms and constructions within the scope of this invention, as would be apparent to one skilled in the art, it is to be understood that the particular form shown is but one of such embodiments. With various modifications and changes being possible, it is necessary to point out that the invention is not limited in any way with respect thereto. Moreover, it is to be understood that certain features of this invention can be employed without a corresponding use of other features thereof.

Accordingly, what is claimed as new is:

1. A substantially scrapless die layout apparatus for a core lamination including a pair of opposed T-shaped yoke laminae and elongated leg laminae, said apparatus comprising an elongated die punch, an elongated die bed, a series of punch members located in a plurality of positions along the length of said die punch, means for progressively feeding a strip member by sections through stages of said apparatus adjacent one end of said series of punches, a first of said punch members being shaped for cutting out a first one of said T-shaped lamina at a position inwardly of one end of a section of said strip member, a second of said punch members being shaped for cutting out a second one of said T-shaped lamina, said second punch member having its head portion juxtaposed to the head portion of the first T-shaped punch and with its foot located inwardly of the other end of said section, whereby said first and second punchings together define a cruciform opening in the strip member, a further punch member including means for separating in equal portions the remaining part of said section for forming the leg laminae of said core lamination between cross portions of adjacent cruciforms, said die bed having corresponding cavities in registration with each of said punch members, chutes located at least under some of said cavities for collecting the punched out portions in a stacked manner, a separator adjacent the other end of said series of punch members disposed to engage leg laminae, said cavities and said separator providing for the orderly emission of the components from said strip member as said strip progresses stage by stage through said apparatus.

2. A substantially scrapless die layout apparatus for a core lamination including a pair of opposed T-shaped yoke laminae and elongated leg laminae, said apparatus comprising an elongated die punch, an elongated die bed, a series of punch members located in a plurality of positions along the length of said die punch, means for progressively feeding a strip member by sections through stages of said apparatus adjacent one end of said series of punches, a first of said punch members being shaped for cutting out a first one of said T-shaped lamina at a position inwardly of one end of a section of said strip member, a second of said punch members being shaped for cutting out a second one of said T-shaped lamina, said second punch member having its head portion juxtaposed to the head portion of the first T-shaped punch and with its foot located inwardly of the other end of said section, whereby said first and second punchings together define a cruciform opening in the strip member, a further punch member including means for separating in equal portions the remaining part of said section for forming the leg laminae of said core lamination between cross portions of adjacent cruciforms, said die bed having corresponding cavities in registration with each of said punch members, chutes located at least under some of said cavities for collecting the punched out portions in a stacked manner, a generally wedge-shaped stationary separator adjacent the other end of said series of punch members disposed to engage and separate leg laminae as the strip is advanced to the next stage, said cavities and said separator providing for the orderly emission of the components from said strip member as said strip progresses stage by stage through said apparatus.

3. A method for producing a core lamination including a pair of opposed T-shaped yoke laminae and elongated leg laminae punched from a strip member of electrical steel, said strip member having a width substantially equal to the width of twice the leg lamina plus the width of the foot of said T-shaped yoke lamina: said method comprising, punching said pair of T-shaped yoke laminae from a central portion of said strip member as said member is moved progressively by stages through a punching machine, albeit in a predetermined geometrical arrangement of the individual laminae along the direction of movement of said strip member, wherein a first one of said T-shaped yoke lamina having its head portion extending laterally across said strip member and its foot portion extending opposite to the direction of travel of said strip member, the second of said T-shaped yoke lamina having its head portion abutting the head portion of said rst yoke lamina and its foot portion extending in the direction of travel of said strip member, the outer periphery of said first and second yoke laminae defining the inner periphery of adjacent portions, said leg laminae located on opposite sides thereof and generally extending in the direction of travel of 5 said strip member, severing said leg laminae laterally and longitudinally from said strip member to define the remainder of the periphery thereof, whereby the laminae arrangement results in an essentially scrapless core lamination, and separating and collecting the individual lamina 10 for assembly to form said core.

References Cited in the le of this patent UNITED STATES PATENTS Thordarson Oct. 19, Philip Sept. 24, Doyle Apr. 28, Murch Feb. 6, Blair June 17, Feinberg `Tune 30, Moynihan June 28, 

1. A SUBSTANTIALLY SCRAPLESS DIE LAYOUT APPARATUS FOR A CORE LAMINATION INCLUDING A PAIR OF OPPOSED T-SHAPED YOKE LAMINAE AND ELONGATED LEG LAMINAE, SAID APPARATUS COMPRISING AN ELONGATED DIE PUNCH, AN ELONGATED DIE BED, A SERIES OF PUNCH MEMBERS LOCATED IN A PLURALITY OF POSITIONS ALONG THE LENGTH OF SAID DIE PUNCH, MEANS FOR PROGRESSIVELY FEEDING A STRIP MEMBER BY SECTIONS THROUGH STAGES OF SAID APPARATUS ADJACENT ONE END OF SAID SERIES OF PUNCHES, A FIRST OF SAID PUNCH MEMBERS BEING SHAPED FOR CUTTING OUT A FIRST ONE OF SAID T-SHAPED LAMINA AT A POSITION INWARDLY OF ONE END OF A SECTION OF SAID STRIP MEMBER, A SECOND OF SAID PUNCH MEMBERS BEING SHAPED FOR CUTTING OUT A SECOND ONE OF SAID T-SHAPED LAMINA, SAID SECOND PUNCH MEMBER HAVING ITS HEAD PORTION JUXTAPOSED TO THE HEAD PORTION OF THE FIRST T-SHAPED PUNCH AND WITH ITS FOOT LOCATED INWARDLY OF THE OTHER END OF SAID SECTION, WHEREBY SAID FIRST AND SECOND PUNCHINGS TOGETHER DEFINE A CRUCIFORM OPENING IN THE STRIP MEMBER, A FURTHER PUNCH MEMBER INCLUDING MEANS FOR SEPARATING IN EQUAL PORTIONS THE REMAINING PART OF SAID SECTION FOR FORMING THE LEG LAMINAE OF SAID CORE LAMINATION BETWEEN CROSS PORTIONS OF ADJACENT CRUCIFORMS, SAID DIE BED HAVING CORRESPONDING CAVITIES IN REGISTRATION WITH EACH OF SAID PUNCH MEMBERS, CHUTES LOCATED AT LEAST UNDER SOME OF SAID CAVITIES FOR COLLECTING THE PUNCHED OUT PORTIONS IN A STACKED MANNER, A SEPARATOR ADJACENT THE OTHER END OF SAID SEIES OF PUNCH MEMBERS DISPOSED TO ENGAGE LEG LAMINAE, SAID CAVITIES AND SAID SEPARATOR PROVIDING FOR THE ORDERLY EMISSION OF THE COMPONENTS FROM SAID STRIP MEMBER AS SAID STRIP PROGRESSES STAGE BY STAGE THROUGH SAID APPARATUS. 